[clang][doc] Simplify Sampling-PGO use example (#162588)

The -fprofile-sample-use implies codegenoptions::LocTrackingOnly. No
need to explicitly specify -g if debug info is not required in final binary.

Also fix -fuse-ld=lld.

Author: HaohaiWen

clang/docs/UsersManual.rst

@@ -2778,7 +2778,7 @@ usual build cycle when using sample profilers for optimization:
 
      > clang-cl /O2 -gdwarf -gline-tables-only ^
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
-       code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
+       code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf
 
 .. note::
 
@@ -2861,23 +2861,25 @@ usual build cycle when using sample profilers for optimization:
    that executes faster than the original one. Note that you are not
    required to build the code with the exact same arguments that you
    used in the first step. The only requirement is that you build the code
-   with the same debug info options and ``-fprofile-sample-use``.
+   with the same debug info options and ``-fprofile-sample-use``. ``-gdwarf``
+   and ``-gline-tables-only`` can be omitted if you do not need debug info
+   in the final binary.
 
    On Linux:
 
    .. code-block:: console
 
-     $ clang++ -O2 -gline-tables-only \
+     $ clang++ -O2 \
        -fdebug-info-for-profiling -funique-internal-linkage-names \
        -fprofile-sample-use=code.prof code.cc -o code
 
    On Windows:
 
    .. code-block:: winbatch
 
-     > clang-cl /O2 -gdwarf -gline-tables-only ^
+     > clang-cl /O2 ^
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
-       -fprofile-sample-use=code.prof code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf
+       -fprofile-sample-use=code.prof code.cc /Fe:code
 
    [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/
    edge counters. The profile inference algorithm (profi) can be used to infer
@@ -2886,17 +2888,17 @@ usual build cycle when using sample profilers for optimization:
 
    .. code-block:: console
 
-     $ clang++ -fsample-profile-use-profi -O2 -gline-tables-only \
+     $ clang++ -fsample-profile-use-profi -O2 \
        -fdebug-info-for-profiling -funique-internal-linkage-names \
        -fprofile-sample-use=code.prof code.cc -o code
 
    On Windows:
 
    .. code-block:: winbatch
 
-     > clang-cl /clang:-fsample-profile-use-profi /O2 -gdwarf -gline-tables-only ^
+     > clang-cl /clang:-fsample-profile-use-profi /O2 ^
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
-       -fprofile-sample-use=code.prof code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf
+       -fprofile-sample-use=code.prof code.cc /Fe:code
 
 Sample Profile Formats
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